Invasive Cardiology Digital Signal Amplifier and Acquisition Device

ABSTRACT

The digital signal amplifier and acquisition system includes at least one catheter input module (CIM) configured to receive, route and digitize incoming analog cardiac signals from a number of catheters, as well as outgoing stimulator pulses. A plurality of CIMs are mechanically stacked and electrically daisy-chained and coupled with a mounting. The mounting platter is clamped to the bedrail and provides a single digital output cable to the base. The system also includes an acquisition device and the aforementioned base, which is configured to collect, filter and distribute the acquired data. Lastly an analog output module receives filtered digital signals from the base and is configured to reconstruct analog representations of such filtered digital signals for outside devices.

RELATED APPLICATIONS

The present application is based on and claims priority to U.S.Provisional Patent Application Ser. No. 60/800,370, filed May 15, 2006.

FIELD OF THE INVENTION

The subject matter described herein generally relates to the field ofinvasive cardiology, and, more particularly, to the invention relates tothe field of digital signal amplification and acquisition systems.

BACKGROUND OF THE INVENTION

In order to properly and accurately diagnose cardiac conditions, it isimportant for the physician to have clear and clean cardiograms at hisor her disposal. Therefore, an acquisition system for cardiac behaviormust capture electrophysiological signals accurately as small as 6 uV.These signals must be captured with very little noise, and displayed,stored and sent to other medical equipment in a real-time manner.

These electrophysiological signals must be filtered in a number of waysand the captured data within the signals must reject artifacts caused byother equipment, such as pacemaker or ablation devices. Current systemsoffer various trade-offs in terms of speed, noise and resolution. Inother words, the additional cabling in all current systems acts as anantenna for stray electromagnetic signals, and as a result, constitutesa primary noise source in those systems. Many current systems have 16 orless bits of A/D resolution and sample at typical low ranges of 1 to 2KHz. Furthermore, current systems do not typically embody a quickreal-time response for data capture and display, nor do they includecomplete modularity.

BRIEF DESCRIPTION OF THE INVENTION

The digital signal amplifier and acquisition system includes at leastone catheter input module (CIM) configured to receive, route anddigitize incoming analog cardiac signals from a number of catheters, aswell as outgoing stimulator pulses. A plurality of CIMs are mechanicallystacked and electrically daisy-chained and coupled with a mountingplatter. The mounting platter is clamped to the bedrail and provides asingle digital cable to the base. The system also includes anacquisition device and the aforementioned base, which is configured tocollect, filter and distribute the acquired data. Lastly an analogoutput module receives filtered digital signals from the base and isconfigured to reconstruct analog representations of such filtereddigital signals for outside devices.

In one embodiment, an invasive cardiology digital signal amplifier andacquisition system is provided. The system includes at least onecatheter input module, the at least one catheter input module configuredto receive a set of analog cardiac data from a patient catheter, the atleast one catheter input module including a digitizer configured toconvert the set of analog cardiac data to a set of digital data, a mountplatter mechanically and electrically coupled to the at least onecatheter input module, the mount platter configured to receive the setof digital data from the at least one catheter, and a base unit coupledwith the mount platter with a digital cable, the base unit configured toreceive the set of digital data, and further configured to filter anddistribute the set of digital data. The system further comprises ananalog output module coupled with the base unit and configured toreceive a filtered set of digital data from the base unit, and furtherconfigured to convert the filtered set of digital data to areconstructed analog signal, an acquisition device coupled with the baseunit, the acquisition device configured to control the collection of aplurality of physiological parameters from a patient and wherein themount platter includes an emergency stimulator connector configured toprovide a pulse to the patient catheter even in the event of totalsystem failure, which may include an auxiliary reference inputconfigured to collect a non-catheter patient input. The system furtherwherein the at least one catheter input module includes a plurality ofinputs, the mount platter includes a test signal generator configured totest the functionality of any of the plurality of inputs of the catheterinput module and wherein each of the plurality of catheter input modulesis electrically and mechanically coupled to each other and with themount table wherein the mount platter is fastened to a patient bed.

In another embodiment, a method of cardiology signal acquisition andamplification is provided. The method comprises the steps of collectinga set of analog cardiac data from a patient catheter, converting the setof analog cardiac data to a set of digital data with a cardiac inputmodule, the cardiac input module including an analog to digitalconverter, collecting the set of digital data with a mount platter,transmitting the set of digital data to a base unit, wherein the baseunit is configured to filter and distribute the set of digital data andcomprises receiving a filtered set of digital data in an analog outputmodule from the base unit, wherein the analog output module isconfigured to convert the filtered set of digital data to areconstructed analog signal. The method further comprises coupling anacquisition device coupled with the base unit, the acquisition deviceconfigured to control the collection of a plurality of physiologicalparameters from a patient wherein the mount platter includes anemergency stimulator connector configured to provide a pulse to thepatient catheter even in the event of total system failure the mountplatter including a auxiliary reference input configured to collect anon-catheter patient input wherein the at least one catheter inputmodule includes a plurality of inputs, and further wherein the mountplatter includes a test signal generator configured to test thefunctionality of any of the plurality of inputs of the catheter inputmodule, and wherein at least one catheter input module is a plurality ofcatheter input modules, wherein each of the plurality of catheter inputmodules is electrically and mechanically coupled to each other and withthe mount table wherein the mount platter is fastened to a patient bed.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 illustrates an embodiment of a block diagram of a method ofsignal acquisition and amplification.

FIG. 2 illustrates a schematic diagram of an embodiment of digitalamplifier and acquisition system.

FIG. 3 illustrates a graphical representation of another embodiment ofthe system of a digital amplifier and acquisition system.

DETAILED DESCRIPTION

The digital signal amplifier and acquisition system relocates thecardiac signal digitization from a point many feet away from thepatient, up to the patient's bedside, thereby eliminating a significantamount of noise induced by analog cabling. It has been found that analogcabling causes approximately half of the noise found in currentacquisition systems, and current systems include catheter input modules(CIMs) that do not include digitizers, but rather act only as inputswith analog cables that connect to the digitizer, typically in the baseseveral feet away, or attached to the underside of the bed. The presentdigital signal amplifier and acquisition system also directly convertsthe analog signal to a digital signal without amplifying the analogsignal or applying any band pass filtering, which also reduces asignificant amount of signal noise.

FIG. 1 shows an embodiment of the acquisition system 100 that includesone or more catheter input modules (CIM) 102 which have a technicaleffect to receive incoming cardiac signals from a catheter, and routeand digitize those signals. The system 100 will be able to accommodatefour such CIMs, each with 30 channels for a total of 120 channels. Thecatheters (not shown) will connect via the 6, 10-pin connectors 103, ineach of the CIMs 102. As illustrated in FIG. 1, all of the CIMs 102 aremanually stacked and electrically daisy-chained (FIG. 2) via a shortcable on the rear of the CIM 102, and held on the patient's bedside witha mount platter 104. The CIM 102 is a 4 KHz 24-bit sigma delta A/Ddigitizer, bipolar or unipolar with respect to a Wilson central terminalor auxiliary reference, respectively.

Still referring to FIG. 1, the mount platter 104 is configured to holdand support the CIMs 102, and provide emergency and reference inputsources 105, 107, 109. The mount platter 104 utilizes an attachment pole106 in order to clamp the mount platter 104 to the bedrail of thepatient's bed. The mount platter 104 also includes a single CIM cable108, which provides digital signals from the CIMs 102 to the base 120.The mount platter 104 also includes emergency stimulator connectors 105,as well as an auxiliary reference input 107 and a test signal generator109. The emergency stimulator connectors 105 provide the ability toutilize the catheters placed in the patient as emergency pacemakers inthe event of total failure of the system 100. The emergency stimulatorconnectors 105 provide for a direct electrical connection to the STIMinputs number 1 and 2 provided on the STIM connector 127 on the baseunit 120. The auxiliary reference input 107 allows a physician to buildan analog channel without using a catheter and the CIMs 102. In otherwords, a physician may utilize a device such as a patch on the back ofthe patient or an electrode in the leg of the patient and plug thisdevice into the auxiliary reference input 107 to provide an additionalinput. The test input 109 allows a test of any of the CIMs 102 byplugging a connector from the test input 109 into any of the ten pinconnectors 103 in any of the CIMs 102 in order to see if the CIM 102 isworking properly.

Referring now to FIGS. 1 and 2 the system 100 also includes anacquisition module 110 and a base 120. The base 120 is configured toreceive the digital signals from the mount platter 104 through the CIMcable 108 and filters and distributes this acquired data. The base 120is also configured to give a digital command to the CIMs 102 in order toinstruct the CIMs 102 when to digitize the information, and is furtherconfigured to package the digital data from the CIMs 102 in order tosend it to a PC or outside device for additional processing. The base120 is preferably mounted on the base of the patient's bed 210 (FIG. 3).The acquisition device 110 is mechanically and electrically coupled withthe base, and is configured to collect a number of physiologicalparameters from the patient such as blood pressure, heart rate,respiratory data, and blood oxygen saturation level. The base 120includes 8 bipolar simulator inputs which are digitized and routed, 4analog inputs, which are digitized in synchronous with CIM sampling, 12lead ECG and 4 IBP analog signals shared with the acquisition module110, and 16 low-latency analog outputs.

Referring back to FIG. 1, the base 120 includes an analog out 122, whichprovides a digital signal through the cable 132 to the analog outputmodule 130. The base 120 also includes an analog input 124, a vital signoutput 126, a simulator input 127 and a network connection 128.Referring again to FIG. 2, the stimulator input 127 receives inputs fromthe stimulator 135, while the outside devices 140 send request andreceive processed and filtered data from the base 120 for physicianreview.

The system 100 also includes an analog output module 130. The analogoutput module 130 is configured to receive a digital signal from theanalog out 122 of the base 120 through the cable 132, and reconstruct ananalog signal, preferably with up to 16 filtered digital data streams ata time. The analog output module 130 is configured to reconstruct theanalog signal for a strip chart recorder, or any other outside devicethat requires a representation of the signal.

Referring now to FIG. 3, a graphical representation of an embodiment ofthe system 100 of the present invention is depicted. Here, the catheters220 are connected into the CIMs 102, which are mechanically stacked anddaisy-chained to the mount platter 104. The attachment pole 106 allowsthe mount platter 104 to be attached to the bedrail of the patient's bed210, and a single CIM cable 108 allows digital signals to becommunicated from the mount platter 104 to and from the base 120. As isshown, the base 120 is mounted on the patient bed 210 and an acquisitiondevice 110 is coupled with the base 120.

The system 100 reduces a large amount of system noise by digitizing theanalog signals at a close proximity to the patient, eliminating manyfeet of analog cable from the systems of the prior art. Furthermore, alarge amount of system noise is removed by eliminating analog switchingand filtering circuits, which is done by performing all signalprocessing after the CIMs in the digital domain.

Furthermore, an embodiment utilizes a 4 KHz, 24-bit A/D converter whichprovides greater than 20 bits of signal resolution when noise isaccounted for. This large number of bits provides the system 100 theability to record signals down to the physiological minimal level ofinterest of 6 uV over an input range of almost 5 volts. A range andresolution this large allows for recording all data of interest even innon-ideal conditions such as pacemaking or ablating. In other words, thesystem 100 has a much higher resolution and range than conventionalsystems.

The system 100 of the present invention also embodies a real-timeresponse. It is important that data be captured and displayed or sent toother equipment as quickly as possible in such systems. The digital base120 of the system 100 includes a high-speed processor and programmablelogic able to receive over 150 channels of data at 24 bits and 4 KHz.Preferably, the data is placed in Ethernet frames and sent at 250 Hz atthe same time it is filtered and sent out in analog form in less than 2mS.

Furthermore, the system 100 of the present invention is versatile from amarket standpoint, as it incorporates a set of modular CIMs 102.Preferably, each CIM 102 accepts 60 inputs, captures 30 unipolar orbipolar channels, and the system 100 is configured to support from 1 to4 CIMs 102. Additionally, two analog outputs are provided on the base120, and with additional analog output module support, such analogoutputs are expanded to 16 outputs.

Subject matter has been described in terms of specific embodimentsincorporating details to facilitate the understanding of the principalsof construction and operation of the invention. Such reference herein tospecific embodiments and details thereof is not intended to limit thescope of the claims appended hereto. It will be apparent to thoseskilled in the art that modifications may be made in the embodimentchosen for illustration without departing from the spirit and scope ofthe invention.

1.-9. (canceled)
 10. A method of cardiology signal acquisition andamplification for distribution to at least a display, the methodcomprising the steps of: collecting a set of analog cardiac data from apatient catheter with a cardiac input module; converting the set ofanalog cardiac data directly to a set of digital data within the cardiacinput module without amplification; removably coupling a mount platterto a patient bed, such that the mount platter is coupled with hecatheter input module and holds the catheter input module; communicatingthe set of digital data from the cardiac input module to the mountplatter; communicating the set of digital data from the mount platter toa base unit, wherein the base unit is coupled with the patient bed andis configured to filter and distribute the set if digital data forillustration on the display, wherein the mount platter is furtherconfigured to support a plurality of catheter input modules in a stackedconfiguration, further wherein the mount platter and each of theplurality of catheter input modules are electrically coupled to oneanother.
 11. The method as claimed in claim 10, further comprisingreceiving a filtered set of digital data in an analog output module fromthe base unit, wherein the analog output module is configured to convertthe filtered set of digital data to a reconstructed analog signal. 12.The method as claimed in claim 10, further comprising coupling anacquisition device with the base unit, the acquisition device configuredto control the collection of a plurality of physiological parametersfrom a patient.
 13. The method as claimed in claim 10, wherein the mountplatter includes an emergency stimulator connector configured to providea pulse to the patient catheter in the event of total system failure.14. The method as claimed in claim 10, wherein the mount platterincludes an auxiliary reference input configured to collect anon-catheter patient input.
 15. The method as claimed in claim 10,wherein the catheter input module includes a plurality of inputs. 16.The method as claimed in claim 15, wherein the mount platter includes atest signal generator configured to test the functionality of any of theplurality of inputs of the catheter input module.
 17. (canceled)
 18. Themethod as claimed in claim 10, wherein the mount platter is fastened toa patient bed.